Improvement in head-blocks for saw-mills



- F. N. WHITCDMB.

j Head-Black forSaw-Mills.

N0 150'982. i Pmmedmarchfnes.`.

` l W T ss INV TOR l W I NE ES ATTORNEYS THE GRAPHIC C.PHOT0.-UTH.39 841 'PARK PLACEJLY.

spring on the knee which i UNITED STATES PATENT EEIGE,

FRANCIS N. WHITGOMB, OF'AMI-TY, NEW YORK.

IMPROVEMENT IN` HEAD-BLOCKS FOR SAW-MILLS.

Specification forming part of Letters Patent N0. 160,982, dated March16, 1875.; application filed December 14, 1874.

GAsE A.

To all whom t may concern:

Be it known that I, FRANCIS N. WHITCOMB, of Amity, in the county ofOrange and in the State of New York, have invented certain new anduseful Improvements in Head-Blocks for Saw-Mills; and do hereby declarethat the following is a full, clear, and exact description thereof,reference being had to the accompanying drawings, and to the letters ofreference marked thereon, making a part of this specification.

My invention relates to improvements in head-blocks; and it consists,rst, in combining, with a head-block knee having a rack-bar on its underside, of a gear-wheel mounted on a counter-shaft, and anv inclosedcoiled steel i spring upon the same shaft for retractin g the head-blockknee after the same has been brought forward; second, in the employmentof a studupon the coiled-spring casing, which acts in conjunction with astationary stud on the head-block, upon which the log lrests for thepurpose of winding the spring which recedes the knee 5 third, in theemployment of a stepped-faced cam arranged on the countershaft, incombination with an angular lever, connecting-rod, and hand-lever, forthe purpose of adjusting the distance of the retraction of the knee;fourth, in a dog, which is "pivoted upon a detachable vertical shaft,having a projecting arm, in combination with a bears against theprojecting arm, for the purpose of throwing the dog rearward out ofposition when the dog is taken from the log, for the purpose ofpreventing injury to the saw; fifth, in the combination of a graduatedscale adjacent to the hand-lever and the notched or stepped cam on thecounter-shaft, which stops the knee as it recedes at any given point.

To enable others skilled in the art to construct my invention, I willproceed to describe the same more fully in detail, referring to theannexed drawings, in which- Figure l represents a plan view. Fig. 2represents a side elevation with the lines broken to show the rack-baron the knee,'the gearwheel, pinion, and retracting coil-spring. Fig.

3 represents the graduated arc and two leversv connected thereto, aswell as their connectingrods for the angular levers, which take into thenotches in the stepped cams. Fig. 4 is a perspective view of one form ofthe stepped cam. Fig. 5 is a view of the two faces of another form ofthe stepped cam which may be employed.

In the accompanying drawings, A represents the usual'form of saw-millcarriage upon which is placed two or more head blocks and knees. Brepresents the headblock, and C represents the knee, which is providedon its horizontal under portion with a rack-bar, H. This knee and itsrack-bar move back and forth through a slot in the head-block. Extendingcrosswise through the block B at the rear is a shaft,

D, which projects beyond the head-block, andV is journaled at one end toa casting connected to the carriage, and provided at said journal with ahand-lever, D. At each side of the head-block, and surrounding the shaftD, are sleeves, which are, by connecting-links, at-

tached to shells or castings which contain pawls, which take intoratchets on a shaft, G, which also extends through Vthe head-block Vandinfront of the shaft D. This shaft Gr has also a pinion, I, which takesinto the rack H on the under part of the knee. In front of the shaft G,and secured to the under part of the head-block by suitable adjustableboxes, is a large gear-wheel, O, which gears into the pinion I on theshaft G. On one end of this shaft is secured a coiled steel spring, L,inclosed in a circular box, L. On the other end of this shaft is a disk,M, having a step-shaped flange, M', which extends at right anglesoutwardly from its face. The casing L of the spring has an arm, b, uponits periphery, and the side of the head-block has a stud, e, so that, asthe knee G is fed forward, the arm on the casing will strike againsttheV stud, andas the knee is fed farther forward the spring in thecasing will` be wound up, as more fully hereinafter set forth. Prepresents a lever, which is pivoted to the front part of one side ofthe head-block, and extends parallel therewith near to thestepped-shaped cam M, where it is provided with an L-shaped bend, asshown in Fig. 1. The rear end of `this lever is attached to a horizontalconnectingrod, Q, extendingat right angles, and which rod is pivoted tothe lower end of a vertical hand-lever, S, secured to a casting on thecarriage. The top portion of this casting T is made on a curve, andnotched for the lever to be caught in any one of the notches desired.Near each of these notches is affixed -a number to indicate, through themedium of the cam M, the k`f^"^^ distance of the knee C is in or out onthe headblock, as hereinafter described. E represents a scale of notchesto designate the number of boards or plank in the cant. A" represents ashort shaft having a cam to engage and disengage the pawls in the shellsF. W represents the dog which holds the log. This dog is pivoted to astem, w, having one arm, '11, and is fitted into a socket made thereforin the kre lf Secured to the knee is a spring, of any suitable form orconstruction, which is adjacent to the arm v on the stem to which thedog is pivoted, so that as soon as the dog is released from the log, thespring will throw the dog around out of the way of the saw. A studshould be placed on the top of the stem to 4 prevent too violent a throwof the dog, and

its being thrown too far rearward.

I In Fig. 5 the form of the stepped cam is slightly changed from thatshown in Figs. l and 4. In the form seen in Fig. 5 the notches M' are onthe face of the disk. The reverse of the plate would have acounter-balance, kas seen at M", to cause it to rotate in properposition.

In the use of the form seen in Fig. 5 it would be necessary to place thelever P at right angles or turned upward from its present position, sothat its angle would act upon the notches, and a crank would then benecessary to raise upward the bend of the lever from the notches in thecam. It will be understood that it is customary to employ two or morehead-blocks (in sawing lumber) at one time; hence it is beneficial touse two levers, S S', one operating upon one head-block and the otherupon the other head-block. To this end I employ two levers within thearc T, so that one lever may operate to set back the knee at any numberof inches required, and the other remain stationary, or be operated toremove a knee back a greater or less distance; and they may both beoperated to throw the two knees back the same distance. In other words,the knees, by means of these levers, may be adjusted independently ortogether, as desired. In operating the levers together the tops thereofare so bent that a ring may clasp them both for operating them at onemovement.

The operation of my head-block is substantially as follows: The lever Sis irst set in a notch in the graduated arc T, according to the size ininches of the diameter of the log i to be sawed. This movement of thelever draws the lever l? out, so that it will set to a correspondingnotch in the step-cam M, and

after the knee is fed forward, will check or retard its backwardmovement at the point, ac-

cording to the number of inches of the width of the log correspondingwith the notches on the arc and those on the cam. As the lever D isoperated, the pawls and ratchets rotate the shaft G, and the pinion Imoves the knee forward by taking into the rack H; the pinion I alsobackwardly revolving the shaft K through the medium of the gear-wheel Owhen the pawls are released. In the forward movement of the knee thegear-wheel O carries with it the casing L' and spring L, as well as thecam M, until the casing revolves far enough for the arm b to strikeagainst the stud e. The casing then stops and the shaft K with itssleeve to which the spring is attached, continues to revolve, and as itdoes the spring L is'coiled around tightly. Then as soon as the lever A"isthrown back the dogs are released from the ratchets and the recoil ofthe spring will throw the knee back until the cam M revolves, so thatthe lever P will catch against the notch set for it to strike, and therebe held.

I do not confine myself to any particular position of placing the cam M,spring L, and casing and gear-wheel O, as they may be placed in anysuitable operating positions with respect to the knee and the feedingmechanism therefor; nor do I wish to be understood as confining myselfto the use of said elements with any particular form of knee orhead-block.

It will be seen that with myinvention there is nothing to retard theforward movement of the knee until after the casing L' has been rotated,so that the arm b strikes the stud e, hence the operation of the knee iseasy and free until the spring begins to wind, and the knee is at apoint where the log has been greatly reduced, and no great exertion isrequired to then force forward the knee.

In all head-blocks known to me where a spring has been used to retractthe knee, the operator, in forwarding the knee to the saw, must exertgreat pressure, inasmuch as the spring begins to coil at once, and thelog at that time being large the power required to force forward theknee must of a necessity be very great. With my invention I obviatecoiling the spring until the log is lightened, hence I require butlittle power to forward the knee.

My spring is completely inclosed in the casing L', so that sawdust,dirt, 85e., cannot get between the coils of the spring to aifect theoperation of the same.

I am aware th at a head-block knee has been retracted by a spring afterthe same has been fed forward to the log; hence Ido not broadly claimsuch as my invention.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is l l. The combination, with theknee C, rackbar H, and pinion I, of the counter-shaft K, gear-wheel O,and coiled spring L inclosed within the casing L', substantially as andfor the purposes herein set forth.

2. The combination of the arm b on the spring-casing L' with the stud eon the headblock, as and for the purposes set forth.

3. The combination of the cam M having notches on its face with theangular lever P and the retracting-knee C, substantially as and for thepurposes herein set forth.

4. The combination of the removable stem w, having a projecting arm, V,the dog W pivoted to the stem and the spring attached to the knee andbearing against the arm V, all constructed substantially as set forth.

5. The combination of a graduated scale, T, With the hand-lever S,connecting-rod O, angular lever P, and stepped cam M, substantialiy asand for the purposes herein set forth.

In testimony that I claim the foregoing I have hereunto set my hand this12th day of December, 1874.

F. N. WHITCOMB. Witnesses:

J. M. MASON, E. A. HALL.

